Clinicopathological correlation in biopsy-proven atherosclerotic nephropathy: implications for renal functional outcome in atherosclerotic renovascular disease

Background. Atherosclerotic renovascular disease (ARVD) is commonly associa ted with renal failure. It is now recognized that intrarenal damage, (ischa emic or atherosclerotic nephropathy) is a major contributor to the renal im pairment nt in these patients. In this study the impact of histological cha nges upon renal functional outcome was investigated in patients with athero sclerotic nephropathy. Methods. The Hope Hospital renal biopsy database (1985 1998) was interrogat ed for patients with histology compatible with atherosclerotic nephropathy. Case-note review enabled the assessment of several clinical parameters and outcomes, including change in creatinine clearance per year (Delta CrCl (m l/min/year)), blood pressure control, dialysis need, and death. Renal paren chymal damage was analysed by morphometric analysis (of interstitial fibros is and glomerulosclerosis) and a semi-quantitative chronic damage score (sc ore 0 3 (normal-severe) for each of glomerulosclerosis, interstitial fibros is, tubular atrophy, and arteriolar hyalinosis; maximum = 12). Patients wer e stratified into two groups who had either deteriorating (group 1) or stab le (group 2) renal function during follow-up. Results. Twenty-five patients (age 64.7+/-10.5, range 43-83 years; 17 male, eight female) were identified. Sixteen patients had undergone angiography; two had significant (>50%) renal artery stenosis. Mean follow-up was 25.6 +/- 14.8 (range 5-50) months. Group 1 patients had Delta CrCl -7.4 +/- 6.8 ml/min/year, n = 14 and group 2 patients had Delta CrCl 4.8 +/- 7.0 ml/min/ year, n = 11. Four patients in group 1 developed end-stage renal disease an d five patients died (three in group 1 and two in group 2). At study entry, group 1 patients had worse renal function (CrCl 27.6 +/- 17.6 vs 36.0 +/- 33.9, NS), greater proteinuria (1.2 vs 0.5 g/24 h, NS), and higher systolic blood pressure (167.1 +/- 30.8 mmHg vs 150.6 +/- 37.8, NS) compared with g roup 2 patients. Group 1 patients showed more glomerulosclerosis (51.6 vs 2 4.9%, P < 0.01), greater proportional interstitial volume (44.9 vs 33.9%, P < 0.02), and higher overall chronic damage score (P < 0.05) than those in group 2. There was a significant correlation between renal functional outco me and chronic damage score, glomerulosclerosis and proportional interstiti al volume for the entire patient cohort. Conclusion. In patients with atherosclerotic nephropathy the severity of hi stopathological damage is an important determinant and predictor of renal f unctional outcome.